[ClusterLabs] Antw: [EXT] Re: What a "high priority"?

[Ken Gaillot]

On Tue, 2021-03-30 at 08:26 +0200, Ulrich Windl wrote:
> > > > Ken Gaillot <kgaillot at redhat.com> schrieb am 29.03.2021 um
> > > > 19:23 in
> 
> Nachricht
> <ceabbfac6cf21b72288d101a050cccdff712f54e.camel at redhat.com>:
> > Scores are in the range ‑1,000,000 to +1,000,000 (also known as
> > "infinity").
> > 
> > Numerically higher scores are preferred in whatever the context is
> > (e.g. higher stickiness means more sticky, higher colocation score
> > means more likely to stay together, etc.).
> 
> So can you confirm that lower-priority resources are relocated
> (moved) first?

Resources are assigned to nodes by highest priority first. That means
higher priority resources are more likely to get their most preferred
node, and are more likely to run if current conditions don't allow all
resources to run.

But which node is a resource's most preferred takes into account a lot
of factors, one of which is that running all resources is considered a
good thing even if a high-priority resource has to move, so priority
won't always translate to which resources move.


> > On Mon, 2021‑03‑29 at 13:05 +0200, Ulrich Windl wrote:
> > > Hi!
> > > 
> > > The question may sound completely stupid, but I didn't find the
> > > formal definition of a "high priority" in the pacemaker docs.
> > > Many years ago I thought lower numbers are higher priorities, but
> > > then I flipped the concept, thinking higher numbers are higher
> > > priorities.
> > > As it seems resource placement (i.e.: relocation) is don using
> > > lower
> > > priorities first, I wonder whether ther is consent among the
> > > developers what a "higher priority" is.
> > > 
> > > Regards,
> > > Ulrich

-- 
Ken Gaillot <kgaillot at redhat.com>